Depression is divided into two general types: primary and secondary type. Under the primary type, the most dominant disorder is Major Depressive Disorder (MDD), also known as clinical depression. MDD is divided into three subtypes: (1) melancholia or classic depression, (2) atypical or non-classic depression, and (3) psychotic depression.

Major subtypes of MDD

• Melancholia is a type of depression where the essential feature is the loss of interest or pleasure in all, or almost all activities, or a lack of reactivity to usually pleasurable stimuli. Your depressed mood does not improve, even temporarily, when something good happens to you. In addition, you experience at least three of the following symptoms: a distinct quality of the depressed mood, depression that is regularly worse in the morning, early morning awakening, psychomotor retardation or agitation, significant anorexia or weight loss, or excessive and inappropriate guilt.
•  In atypical depression, there is mood reactivity and the presence of at least two of the following features:
  • Increased appetite or weight gain
  • Hypersomnia
  • Leaden paralysis
  • The long-standing pattern of extreme sensitivity to perceived interpersonal rejection.

These features predominate during the most recent 2-week period.When you manifest mood reactivity, it means that you cheer up when you are presented with positive events, like a visit from your children, or brothers and sisters, or receiving compliments from others. When you experience hypersomnia, you usually extend your nighttime sleep or daytime napping that totals at least 10 hours of sleep per day. When you are feeling heavy, leaden, weighted down, usually in the arms of legs, then you experience the so-called leaden paralysis.

• In psychotic depression, you are observed to experience delusions, which are false beliefs, wrong judgments, or hallucinations. These are subjective perceptions of what does not exist. In mood-congruent psychotic features, your delusions or hallucinations are consistent with depressive themes. Hence, you may believe that you are responsible for the illness of your loved one, which is an example of delusions of guilt. You may believe that you deserved to be punished because you were not attending masses or religious rites, which is delusions of deserved punishment. In some cases, however, you may manifest mood-incongruent psychotic features such as the belief that an outside force is controlling you (delusions of control), that others could hear your thoughts (delusions of thought broadcasting), or that what you are thinking is not your own (delusions of thought insertion). These delusions do not possess, or not connected with, depressive themes. Thus, they are mood-incongruent.